Two studies with 3-, 4-, and 5-year-olds (N 104) examined whether young children can differentiate expertise in the minds of others. Study 1 revealed that all children in the sample could correctly attribute observable knowledge to familiar experts (i.e., a doctor and a car mechanic). Further, 4- and 5-year-olds could correctly attribute knowledge of underlying scientific principles to the appropriate experts. In contrast, Study 2 demonstrated that 3-, 4-, and 5-year-olds have difficulty making attributions of knowledge of scientific principles to (...) unfamiliar experts. A computational analysis in Study 3 indicated that 4- and 5-year-olds’ successes on the first two studies could not be attributed to the way in which words co-occur in discourse. Overall, these studies showed that young children have a sense of the division of cognitive labor, albeit fragile. (shrink)